org.springframework.jmx.access.MBeanClientInterceptor Maven / Gradle / Ivy
/*
* Copyright 2002-2007 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.jmx.access;
import java.beans.PropertyDescriptor;
import java.io.IOException;
import java.lang.reflect.Method;
import java.net.MalformedURLException;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import javax.management.Attribute;
import javax.management.InstanceNotFoundException;
import javax.management.IntrospectionException;
import javax.management.JMException;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanInfo;
import javax.management.MBeanOperationInfo;
import javax.management.MBeanServer;
import javax.management.MBeanServerConnection;
import javax.management.MalformedObjectNameException;
import javax.management.ObjectName;
import javax.management.ReflectionException;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;
import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.jmx.MBeanServerNotFoundException;
import org.springframework.jmx.support.JmxUtils;
import org.springframework.jmx.support.ObjectNameManager;
/**
* MethodInterceptor implementation that routes calls to an MBean
* running on the supplied MBeanServerConnection. Works for both
* local and remote MBeanServerConnections.
*
* By default, the MBeanClientInterceptor will connect to the
* MBeanServer and cache MBean metadata at startup. This can
* be undesirable when running against a remote MBeanServer
* that may not be running when the application starts. Through setting the
* {@link #setConnectOnStartup(boolean) connectOnStartup} property to "false",
* you can defer this process until the first invocation against the proxy.
*
*
Requires JMX 1.2's MBeanServerConnection feature.
* As a consequence, this class will not work on JMX 1.0.
*
*
This functionality is usually used through MBeanProxyFactoryBean.
* See the javadoc of that class for more information.
*
* @author Rob Harrop
* @author Juergen Hoeller
* @since 1.2
* @see MBeanProxyFactoryBean
* @see #setConnectOnStartup
*/
public class MBeanClientInterceptor implements MethodInterceptor, InitializingBean, DisposableBean {
/** Logger available to subclasses */
protected final Log logger = LogFactory.getLog(getClass());
private MBeanServerConnection server;
private JMXServiceURL serviceUrl;
private String agentId;
private boolean connectOnStartup = true;
private ObjectName objectName;
private boolean useStrictCasing = true;
private JMXConnector connector;
private Map allowedAttributes;
private Map allowedOperations;
private final Map signatureCache = new HashMap();
/**
* Set the MBeanServerConnection used to connect to the
* MBean which all invocations are routed to.
*/
public void setServer(MBeanServerConnection server) {
this.server = server;
}
/**
* Set the service URL of the remote MBeanServer.
*/
public void setServiceUrl(String url) throws MalformedURLException {
this.serviceUrl = new JMXServiceURL(url);
}
/**
* Set the agent id of the MBeanServer to locate.
*
Default is none. If specified, this will result in an
* attempt being made to locate the attendant MBeanServer, unless
* the {@link #setServiceUrl "serviceUrl"} property has been set.
* @see javax.management.MBeanServerFactory#findMBeanServer(String)
*/
public void setAgentId(String agentId) {
this.agentId = agentId;
}
/**
* Set whether or not the proxy should connect to the MBeanServer
* at creation time ("true") or the first time it is invoked ("false").
* Default is "true".
*/
public void setConnectOnStartup(boolean connectOnStartup) {
this.connectOnStartup = connectOnStartup;
}
/**
* Set the ObjectName of the MBean which calls are routed to,
* as ObjectName instance or as String.
*/
public void setObjectName(Object objectName) throws MalformedObjectNameException {
this.objectName = ObjectNameManager.getInstance(objectName);
}
/**
* Set whether to use strict casing for attributes. Enabled by default.
*
When using strict casing, a JavaBean property with a getter such as
* getFoo() translates to an attribute called Foo.
* With strict casing disabled, getFoo() would translate to just
* foo.
*/
public void setUseStrictCasing(boolean useStrictCasing) {
this.useStrictCasing = useStrictCasing;
}
/**
* Ensures that an MBeanServerConnection is configured and attempts to
* detect a local connection if one is not supplied.
*/
public void afterPropertiesSet() throws MBeanServerNotFoundException, MBeanInfoRetrievalException {
if (this.connectOnStartup) {
if (this.server == null) {
connect();
}
retrieveMBeanInfo();
}
}
/**
* Connects to the remote MBeanServer using the configured JMXServiceURL.
* @see #setServiceUrl(String)
* @see #setConnectOnStartup(boolean)
*/
private void connect() throws MBeanServerNotFoundException {
if (this.serviceUrl != null) {
if (logger.isDebugEnabled()) {
logger.debug("Connecting to remote MBeanServer at URL [" + this.serviceUrl + "]");
}
try {
this.connector = JMXConnectorFactory.connect(this.serviceUrl);
this.server = this.connector.getMBeanServerConnection();
}
catch (IOException ex) {
throw new MBeanServerNotFoundException(
"Could not connect to remote MBeanServer at URL [" + this.serviceUrl + "]", ex);
}
}
else {
logger.debug("Attempting to locate local MBeanServer");
this.server = locateMBeanServer(this.agentId);
}
}
/**
* Attempt to locate an existing MBeanServer.
* Called if no {@link #setServiceUrl "serviceUrl"} was specified.
*
The default implementation attempts to find an MBeanServer using
* a standard lookup. Subclasses may override to add additional location logic.
* @param agentId the agent identifier of the MBeanServer to retrieve.
* If this parameter is null, all registered MBeanServers are
* considered.
* @return the MBeanServer if found
* @throws org.springframework.jmx.MBeanServerNotFoundException
* if no MBeanServer could be found
* @see JmxUtils#locateMBeanServer(String)
* @see javax.management.MBeanServerFactory#findMBeanServer(String)
*/
protected MBeanServer locateMBeanServer(String agentId) throws MBeanServerNotFoundException {
return JmxUtils.locateMBeanServer(agentId);
}
/**
* Loads the management interface info for the configured MBean into the caches.
* This information is used by the proxy when determining whether an invocation matches
* a valid operation or attribute on the management interface of the managed resource.
*/
private void retrieveMBeanInfo() throws MBeanServerNotFoundException, MBeanInfoRetrievalException {
try {
MBeanInfo info = this.server.getMBeanInfo(this.objectName);
// get attributes
MBeanAttributeInfo[] attributeInfo = info.getAttributes();
this.allowedAttributes = new HashMap(attributeInfo.length);
for (int x = 0; x < attributeInfo.length; x++) {
this.allowedAttributes.put(attributeInfo[x].getName(), attributeInfo[x]);
}
// get operations
MBeanOperationInfo[] operationInfo = info.getOperations();
this.allowedOperations = new HashMap(operationInfo.length);
for (int x = 0; x < operationInfo.length; x++) {
MBeanOperationInfo opInfo = operationInfo[x];
this.allowedOperations.put(
new MethodCacheKey(
opInfo.getName(), JmxUtils.parameterInfoToTypes(opInfo.getSignature())), opInfo);
}
}
catch (ClassNotFoundException ex) {
throw new MBeanInfoRetrievalException("Unable to locate class specified in method signature", ex);
}
catch (IntrospectionException ex) {
throw new MBeanInfoRetrievalException("Unable to obtain MBean info for bean [" + this.objectName + "]", ex);
}
catch (InstanceNotFoundException ex) {
// if we are this far this shouldn't happen, but...
throw new MBeanInfoRetrievalException("Unable to obtain MBean info for bean [" + this.objectName +
"]: it is likely that this bean was unregistered during the proxy creation process",
ex);
}
catch (ReflectionException ex) {
throw new MBeanInfoRetrievalException("Unable to read MBean info for bean [ " + this.objectName + "]", ex);
}
catch (IOException ex) {
throw new MBeanInfoRetrievalException(
"An IOException occurred when communicating with the MBeanServer. " +
"It is likely that you are communicating with a remote MBeanServer. " +
"Check the inner exception for exact details.", ex);
}
}
/**
* Route the invocation to the configured managed resource. Correctly routes JavaBean property
* access to MBeanServerConnection.get/setAttribute and method invocation to
* MBeanServerConnection.invoke. Any attempt to invoke a method that does not
* correspond to an attribute or operation defined in the management interface of the managed
* resource results in an InvalidInvocationException.
* @param invocation the MethodInvocation to re-route.
* @return the value returned as a result of the re-routed invocation.
* @throws InvocationFailureException if the invocation does not match an attribute or
* operation on the management interface of the resource.
* @throws Throwable typically as the result of an error during invocation
*/
public Object invoke(MethodInvocation invocation) throws Throwable {
// Lazily connect to MBeanServer?
if (!this.connectOnStartup) {
synchronized (this) {
if (this.server == null) {
logger.debug("Lazily establishing MBeanServer connection");
connect();
}
if (this.allowedAttributes == null) {
logger.debug("Lazily initializing MBeanInfo cache");
retrieveMBeanInfo();
}
}
}
try {
PropertyDescriptor pd = BeanUtils.findPropertyForMethod(invocation.getMethod());
if (pd != null) {
return invokeAttribute(pd, invocation);
}
else {
return invokeOperation(invocation.getMethod(), invocation.getArguments());
}
}
catch (JMException ex) {
throw new InvocationFailureException("JMX access failed", ex);
}
catch (IOException ex) {
throw new InvocationFailureException("JMX access failed", ex);
}
}
private Object invokeAttribute(PropertyDescriptor pd, MethodInvocation invocation)
throws JMException, IOException {
String attributeName = JmxUtils.getAttributeName(pd, this.useStrictCasing);
MBeanAttributeInfo inf = (MBeanAttributeInfo) this.allowedAttributes.get(attributeName);
// If no attribute is returned, we know that it is not defined in the
// management interface.
if (inf == null) {
throw new InvalidInvocationException(
"Attribute '" + pd.getName() + "' is not exposed on the management interface");
}
if (invocation.getMethod().equals(pd.getReadMethod())) {
if (inf.isReadable()) {
return this.server.getAttribute(this.objectName, attributeName);
}
else {
throw new InvalidInvocationException("Attribute '" + attributeName + "' is not readable");
}
}
else if (invocation.getMethod().equals(pd.getWriteMethod())) {
if (inf.isWritable()) {
server.setAttribute(this.objectName, new Attribute(attributeName, invocation.getArguments()[0]));
return null;
}
else {
throw new InvalidInvocationException("Attribute '" + attributeName + "' is not writable");
}
}
else {
throw new IllegalStateException(
"Method [" + invocation.getMethod() + "] is neither a bean property getter nor a setter");
}
}
/**
* Routes a method invocation (not a property get/set) to the corresponding
* operation on the managed resource.
* @param method the method corresponding to operation on the managed resource.
* @param args the invocation arguments
* @return the value returned by the method invocation.
*/
private Object invokeOperation(Method method, Object[] args) throws JMException, IOException {
MethodCacheKey key = new MethodCacheKey(method.getName(), method.getParameterTypes());
MBeanOperationInfo info = (MBeanOperationInfo) this.allowedOperations.get(key);
if (info == null) {
throw new InvalidInvocationException("Operation '" + method.getName() +
"' is not exposed on the management interface");
}
String[] signature = null;
synchronized (this.signatureCache) {
signature = (String[]) this.signatureCache.get(method);
if (signature == null) {
signature = JmxUtils.getMethodSignature(method);
this.signatureCache.put(method, signature);
}
}
return this.server.invoke(this.objectName, method.getName(), args, signature);
}
/**
* Closes any JMXConnector that may be managed by this interceptor.
*/
public void destroy() throws Exception {
if (this.connector != null) {
this.connector.close();
}
}
/**
* Simple wrapper class around a method name and its signature.
* Used as the key when caching methods.
*/
private static class MethodCacheKey {
/**
* the name of the method
*/
private final String name;
/**
* the arguments in the method signature.
*/
private final Class[] parameters;
/**
* Create a new instance of MethodCacheKey with the supplied
* method name and parameter list.
*
* @param name the name of the method.
* @param parameters the arguments in the method signature.
*/
public MethodCacheKey(String name, Class[] parameters) {
this.name = name;
if (parameters == null) {
this.parameters = new Class[]{};
}
else {
this.parameters = parameters;
}
}
public boolean equals(Object other) {
if (other == null) {
return false;
}
if (other == this) {
return true;
}
MethodCacheKey otherKey = null;
if (other instanceof MethodCacheKey) {
otherKey = (MethodCacheKey) other;
return this.name.equals(otherKey.name) && Arrays.equals(this.parameters, otherKey.parameters);
}
else {
return false;
}
}
public int hashCode() {
return this.name.hashCode();
}
}
}